Test Socket for Enhancing Integrated Circuit Chip Testing and a Manufacturing Method Thereof

The present invention relates to the semiconductor manufacturing field and, more specifically, to a test socket used for electrical testing of integrated circuit chips.

In the field of electronics manufacturing, testing IC chips is a critical step to ensure the functionality and reliability of the components prior to their deployment in consumer products. Test sockets play a key role in this process by temporarily connecting the IC chips to test equipment, thereby allowing the performance of the IC to be evaluated without permanent soldering.

A primary challenge in designing test sockets is to balance reliable electrical contact with the ability to accommodate various IC chip sizes and configurations. Conventional test sockets often rely on rigid conductive elements that may not adapt well to changes in IC package dimensions or the presence of warpage. Furthermore, maintaining the integrity of electrical contact while preventing short circuits between densely arranged conductive elements remains a persistent problem.

Another important concern is the durability and reliability of the test socket itself. Frequent insertion and removal of IC chips may wear the socket's components, potentially leading to inaccurate test results or the need for frequent replacement. The materials used in the construction of the test socket—including the support structure and the conductive elements—are critical to its overall performance and lifespan.

In view of these challenges, it is apparent that one of ordinary skill in the art would continually seek to innovate test socket designs to provide improved flexibility, reliability, and ease of use.

In order to overcome the above problems, the present invention provides a test socket for enhancing IC chip testing and a manufacturing method thereof. In one aspect, the invention relates to a test socket specifically designed for IC chip testing, combining an advanced structural configuration with a specific manufacturing method. The invention aims to significantly improve the reliability and efficiency of IC chip testing through its unique features.

The test socket comprises an insulating support structure that includes a plurality of through holes. A number of elastic conductive posts are embedded within the support structure and extend through the through holes. Each conductive post comprises a first portion located beneath the insulating support structure and a second portion located above the insulating support structure. A unique feature of the conductive posts is that at least a portion of their circumferential surfaces is covered by an insulating material layer, which is designed to prevent electrical short circuits and ensure stable and reliable electrical contact during testing.

A key innovation of the test socket is its use of specific materials and structural components. The insulating support structure includes both a rigid support frame and a soft support frame. The rigid support frame is fabricated from materials such as polyimide, PCB material, or ceramic, providing the necessary structural rigidity and durability. In contrast, the soft support frame is made of silicone, which offers the flexibility required to accommodate variations arising from IC package warpage or BGA solder ball size tolerances.

Furthermore, the insulating support structure is provided with a plurality of grooves adjacent to the through holes. These grooves help secure the conductive posts within the structure, thereby enhancing the durability of the test socket.

The manufacturing method of the test socket involves forming a layered structure comprising at least one insulating support layer and at least one sacrificial layer. The method includes forming a first set of through holes in the layered structure, filling these holes with an insulating material, and then forming a second set of through holes within the insulating material. Conductive gel is then injected into the second through holes to form the elastic conductive posts. Finally, the sacrificial layer is removed to expose the conductive posts and the insulating support structure, yielding a test socket for IC chip testing.

Thus, the present invention provides a reliable, flexible, and durable solution for IC chip testing by overcoming issues such as potential short circuits or leakage that may occur when the conductive posts deform under pressure during testing.

The present invention relates to a test socket specifically designed for testing integrated circuit (IC) chips. In the electronics field, test sockets establish a reliable electrical connection between the IC chip and test equipment during the evaluation phase. This temporary connection must be precise and stable in order to ensure accurate test results without the need for permanent soldering, which is critical for both the efficiency and cost-effectiveness of IC chip testing.

1 FIG.A 100 100 110 112 120 110 112 120 110 122 110 124 120 126 110 126 124 122 Referring now to, a partial cross-sectional view of a test socketaccording to one embodiment of the present invention is shown. One of the main features of the test socketdisclosed in this embodiment is an insulating support structure, which is provided with a plurality of through holes. Elastic conductive postsare embedded within the insulating support structureand extend through the through holes. In this embodiment, a portion of each elastic conductive postis located below the insulating support structure(hereinafter referred to as the first portion), and another portion is located above the insulating support structure(hereinafter referred to as the second portion). Additionally, each elastic conductive postfurther includes a third portionwithin the insulating support structure, wherein the upper and lower ends of the third portionare respectively connected to the corresponding ends of the second portionand the first portion.

110 114 112 114 120 120 110 100 Moreover, the insulating support structureis further provided with groovesadjacent to the through holes. These groovesaccommodate portions of the elastic conductive posts, thereby ensuring stable attachment between the elastic conductive postsand the insulating support structure, which in turn enhances the durability of the test socketduring testing.

120 121 123 121 120 123 114 112 In the illustrated embodiment, each elastic conductive postcomprises conductive particlesand an elastic material, for example, a silicone-based material. The conductive particlesensure the conductivity of the elastic conductive post, while the elastic materialnot only provides the necessary elasticity but also aids in the overall stability of the connection by adhering to the groovesadjacent to the through holes.

120 130 120 130 130 120 130 122 126 110 130 124 126 110 130 1 FIG.B 1 FIG.C Furthermore, at least a portion of the circumferential surface of the elastic conductive postsis covered by an insulating material layer, which significantly reduces the risk of short circuits during testing, particularly when the elastic conductive postsare deformed under pressure. In this embodiment, the thickness of the insulating material layermay range from 50 to 500 micrometers. The position of the insulating material layeron the elastic conductive postsmay vary according to different designs. For instance, as shown in, the insulating material layermay be located on the first portionand the third portion(situated below the insulating support structure), or, as illustrated in, the insulating material layermay be located on the second portionand the third portion(situated above the insulating support structure). In the present embodiment, the insulating material layeris made of silicone, which is noted for its excellent thermal stability and electrical insulation properties.

2 FIG.A 200 210 212 214 212 210 214 Referring now to, a partial cross-sectional view of another embodiment of a test socketis shown. In this embodiment, the insulating support structurecomprises a rigid support frameand a soft support frame. The rigid support frameprovides overall stiffness and durability to the insulating support structure, while the soft support frameprovides the necessary flexibility to accommodate changes induced by external factors such as IC package warpage or variations in BGA solder ball sizes.

212 210 200 In this embodiment, the rigid support frameof the insulating support structureis made of high-rigidity, high-durability materials such as polyimide, PCB material, or ceramic. Polyimide is well known for its excellent thermal stability, electrical insulation, and mechanical strength, whereas PCB and ceramic materials offer robustness and durability, thereby extending the lifespan of the test socket.

214 212 120 The soft support frameis positioned above the rigid support frameand is generally made of a softer material, such as silicone, which is capable of providing adaptable support for the elastic conductive poststhat may move or deform during testing.

230 120 120 230 214 212 230 120 214 212 120 214 212 230 120 214 120 2 FIG.B 2 FIG.C 2 FIG.D In this embodiment, the insulating material layermay be selectively applied to various portions of the elastic conductive posts. For example, as shown in, the top peripheral region of the elastic conductive postmay not be fully covered by the insulating material layer. Alternatively, as shown in, when the soft support frameis positioned below the rigid support frame, the insulating material layermay be applied not only to the portion of the elastic conductive postadjacent to the upper part of the soft support framebut also to the portion within the rigid support frame, leaving only the bottom periphery of the elastic conductive postexposed. In another alternative, as shown in, the soft support framemay be positioned below the rigid support frame, with the insulating material layerapplied only to the lower portion of the elastic conductive postadjacent to the soft support frame, without fully covering the top and bottom peripheries of the elastic conductive post.

3 FIG. 4 4 FIGS.A toF 4 4 FIGS.A toF 3 FIG. 4 FIG.A 4 FIG.A 110 200 200 200 210 240 240 210 240 210 212 214 240 210 120 Next, referring toin conjunction with, a flowchart of one embodiment of the manufacturing method for the test socket is provided, withbeing schematic diagrams of the test socket at various stages corresponding to the steps outlined in. First, referring to step Sand, a layered structure′ is formed to serve as the molding base for the test socket. The layered structure′ comprises an insulating support layer′ and at least one sacrificial layer(in, a two-layer sacrificial layeris shown), wherein the insulating support layer′ provides the necessary physical and electrical insulation for testing, and the sacrificial layeris subsequently removed. In this embodiment, the insulating support layer′ includes a rigid support layer′ and a soft support layer′. The sacrificial layeris selected for its ease of removal by either mechanical means or chemical means, without damaging the insulating support layer′ or the conductive posts.

120 201 200 201 120 4 FIG.B Then, referring to step Sand, a plurality of first through holesare formed in the layered structure′. The locations of the first through holesare determined by the final positions of the elastic conductive posts, and they are precisely formed using machining tools such as laser cutters, micro-drilling machines, etching equipment, or CNC machining.

130 230 201 230 140 202 230 202 230 120 120 4 FIG.C 4 FIG.D Next, referring to step Sand, an insulating material′ is injected to fill the first through holes. In this embodiment, the insulating material′ is silicone, although those skilled in the art will recognize that other types of insulating materials may be used. Subsequently, referring to step Sand, a second set of through holesis formed in the insulating material′. These second through holes, which are formed within the insulating material′, serve as the locations for filling conductive gel′ to form the elastic conductive posts.

150 120 202 120 121 123 123 120 120 202 120 4 FIG.E 2 FIG.A Then, referring to step Sand, conductive gel′ is injected into the second through holes. The conductive gel′ is a mixture of conductive particlesand an adhesive′ (for example, a silicone-based adhesive), which, upon curing, forms the elastic materialas shown in, thereby forming the elastic conductive posts. It is preferable in this step to inject the conductive gel′ into each of the second through holesin a vacuum environment to avoid air bubbles and ensure consistent performance of the elastic conductive posts.

160 240 240 240 240 120 230 4 FIG.F Next, referring to step Sand, the sacrificial layeris removed. The sacrificial layercan be removed by various methods, such as peeling or chemical dissolution, depending on the material of the sacrificial layer. Removing the sacrificial layerexposes portions of the elastic conductive posts, which are now securely embedded in the insulating support structure.

3 FIG. 2 FIG. 4 FIG.A 1 FIG.A 200 210 212 214 100 It should be noted that although the manufacturing method shown inis used for producing the test socketas illustrated in, those skilled in the art will recognize that by adjusting the steps of the manufacturing method, test sockets according to other embodiments may be produced. For example, referring again to, if the insulating support layer′ comprises only a rigid support layer′ without a soft support layer′, a test socket similar to that shown in(test socket) may be formed.

5 FIG. 6 6 FIGS.A andB 5 FIG. 6 6 FIGS.A andB 5 FIG. 5 FIG. 6 FIG.A 6 FIG.B 3 FIG. 2 2 FIGS.B toD 2 FIG.B 210 230 110 130 240 230 250 230 250 240 250 202 202 230 250 260 270 150 160 210 270 120 230 Alternatively, referring toand,is a flowchart of another embodiment of the manufacturing method for the test socket, andare schematic diagrams illustrating additional stages of the manufacturing method corresponding to the new steps shown in. In, steps Sto Sare identical to steps Sto Sand therefore will not be repeated herein. Next, referring to step Sand, after the insulating material′ is filled, a covering sacrificial layeris formed to cover the insulating material′. In this embodiment, the covering sacrificial layeris made of the same material as the sacrificial layer. Thereafter, referring to step Sand, a second set of through holes′ is formed, wherein the second through holes′ extend through both the insulating material′ and the covering sacrificial layer. The subsequent steps Sand Scorrespond to steps Sand Sin, and therefore are not described in further detail. Following the manufacturing process from step Sthrough step S, a test socket similar to the one shown inis obtained, for example, a test socket in which the top of the elastic conductive postsis not covered by the insulating material layer, as illustrated in.

210 270 214 212 212 120 2 2 FIGS.C toD 2 FIG.D 2 FIG.D Furthermore, by using a manufacturing process similar to steps Sthrough S, test sockets corresponding to those shown incan also be produced. For example (description provided in text only, without corresponding drawings), to produce a test socket as shown in, a layered structure is first formed with a soft support layerpositioned above a first sacrificial layer, followed by the formation of the first through holes. After the insulating material is injected into the first through holes, a rigid support layerand a second sacrificial layer are formed on top of the rigid support layer, and a third sacrificial layer is then applied below the first sacrificial layer. Subsequently, a second through hole is formed within the first through hole, conductive gelis filled and cured, and finally all sacrificial layers are removed, yielding the test socket shown in.

Although the invention has been disclosed and illustrated with reference to particular embodiments, the principles involved are susceptible for use in numerous other embodiments that will be apparent to persons skilled in the art. This invention is, therefore, to be limited only as indicated by the scope of the appended claims.